<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>flex布局</title>
    <style lang="css">
      .box {
        display: flex;
        flex-direction:row ;
        flex-wrap: wrap;
        background-color: #f0f0f0;
        
      }
      .item {
        width: 100px;
        height: 100px;
        background-color: red;
        border: black 1px solid;
      }
      .left {
        flex-basis: 100px;
      }
      .center {
        flex-grow: 1;
      }
      .right {
        flex-basis: 100px;
      }

    </style>
  </head>
  <body>

    <div class="box">
      <div class="item left">left</div>
      <div class="item center">center</div>
      <div class="item right">right</div>
  </body>
</html>
